Error propagation - question

Was wondering if one could get help on how to calculate the error propagation for the following situation:

I have a variable X with an uncertainty ∆X
If R=C/X (where C is a number with no uncertainty), what is the correct way of calculating the uncertainty of R?
Should one use the common propagation of error equation for multiplications/divisions and assume C as having uncertainty of 0 (zero)?

Thanks for the help